“I knew right away” that the bombing was the work of terrorists, Sheri recounted. “My only thing was to get out of there. You were fenced in and you couldn’t get out.”

Sheri stood with Kara’s uncle, Haig Iskenderian, his wife, Andrea, their two children, Lenna and Anna, ages 14 and 12, and a close family friend. Anna was pushed to her knees in the crush of people fleeing Boylston Street. Haig immediately dropped to the ground to shield her from the crowd. All the while, Sheri had no idea whether her daughter was injured or dead. She only knew that she was expected to finish the marathon around the time that the bombs went off.

“I was absolutely hysterical,” Sheri recalled. “I said, I can’t go through this again. It rocked me. It brought you right back.”

Sheri, a Tufts graduate herself, couldn’t reach her daughter, because Kara doesn’t carry a cell phone when she runs. For 45 long minutes, Sheri hung around the finish line, awaiting word about her daughter. Finally, she heard that no runners had been injured in the attacks. Sheri could breathe easier.

She walked 15 minutes to a friend’s apartment to await word from her daughter, who borrowed a phone to text her that she was safe. Kara remained at the hotel, which was locked down, until 9 p.m., when an ESPN reporter gave her a ride to her mother’s location.

Kara returned to Tufts, whose campus was also locked down, on April 19, as authorities closed in on Dzhokhar Tsarnaev. Kara waited in her dormitory’s basement laundry room until he was caught late that night.

The 100-member Tufts marathon team, which comprises students, alumni, professors and university administrators, runs Boston as a fundraiser for the college’s Friedman School of Nutrition Science and Policy. Many of Kara’s teammates were stunned and shaken, emotionally drained by the bombings. She comforted them at a team meeting in the days after the attack.

“A lot of people have never gone through something as tragic as this,” she said. “As horrible as things are when they happen, things improve. No matter how long it takes, things get better.”